Tunable integrated optics led components and methods

ABSTRACT

Light emitting diode (LED) devices and methods. An example apparatus can include a substrate, one or more LEDs, light-transmissive encapsulation material, and a reflective material covering a portion of the encapsulation material to form a defined opening. The opening allows light emitted from an LED to pass through in a prescribed manner. In some embodiments, the apparatus can be subsequently treated to modify the surface having the opening. In other embodiments, the reflective material can be disposed on a lateral surface of the encapsulation material to reflect light in a desired direction.

TECHNICAL FIELD

The subject matter disclosed herein relates generally to light emittingdiodes (LEDs), components, and related methods. More particularly, thesubject matter disclosed herein relates to solid state lightingapparatuses and related methods for controlling light output.

BACKGROUND

Light emitting diodes or “LEDs” are solid state devices that convertelectrical energy into light.

Conventional LED arrays can sometimes have a transparent encapsulantcovering the individual LEDs, such as for protection of the LEDs and tomaximize the efficiency of the devices. When used in some applications,however, it may be desirable to reduce and/or focus the amount ofreflected light. Directing and controlling the amount of light emittedcan provide benefits such as, for example, increased contrast and imagesharpness. One method to achieve this benefit is with the use ofsecondary optical devices, such as lenses. These devices can add costand complexity to an LED apparatus, as well as contributing toefficiency losses. These drawbacks can be avoided by usingcomponent-level integrated optics to direct and control light output.

SUMMARY

Substrate based LEDs and related methods having improved reliability andperformance are provided and described herein. Devices, components, andmethods described herein can advantageously exhibit improved processingtimes, ease of manufacture, and/or lower processing costs. Devices,components, and related methods described herein are well suited for avariety of applications such as personal, industrial, and commerciallighting applications including, for example, light bulbs and lightfixture products and/or applications. In some aspects, devices,components, and related methods described herein can comprise improvedLED manufacturing processes and/or improved optical properties includingimproved light output, contrast, and more consistent and uniform lightemission and color. Such devices can be less expensive and moreefficient.

In some aspects, an LED apparatus can have a substrate, one or more LEDdisposed over the substrate, a light-transmissive encapsulation materialdisposed over the one or more LED, and a reflective material disposed ona portion of the encapsulation material such that the reflectivematerial defines an opening to allow light to escape or pass from theencapsulation material and one or more LED.

In other aspects, a light emitting diode (LED) apparatus can have asubstrate, one or more LED disposed over the substrate, alight-transmissive encapsulation material disposed over the one or moreLED, and a reflective material disposed against one or more lateralsurface of the encapsulation material and in contact with the substrate.

In other aspects, a method of producing an LED apparatus comprisesproviding a substrate with at least one LED disposed over the substrate,applying an encapsulation material over the at least one LED, andapplying a reflective material on a portion of the encapsulationmaterial such that the reflective material defines an opening to allowlight to escape or pass from the encapsulation material and one or moreLED.

In other aspects, a method of controlling light output from an LEDapparatus comprises providing a substrate and one or more light emittingdiode (LED) disposed over the substrate, applying an encapsulationmaterial over the one or more LED, and controlling light output from theone or more LED by applying a layer of reflective material on a portionof the encapsulation material such that the reflective material createsan opening to allow light to escape or pass from the encapsulationmaterial and one or more LED.

These and other objects of the present disclosure as can become apparentfrom the disclosure herein are achieved, at least in whole or in part,by the subject matter disclosed herein.

BRIEF DESCRIPTION OF DRAWINGS

A full and enabling disclosure of the present subject matter is setforth more particularly in the remainder of the specification, includingreference to the accompanying figures, relating to one or moreembodiments, in which:

FIG. 1 is a cross-sectional side view of a prior art LED apparatus;

FIG. 2 is a cross-sectional side view of an embodiment of an LEDapparatus;

FIGS. 3A and 3B are isometric views of a further embodiment of an LEDapparatus;

FIG. 4A is a cross-sectional view of a further embodiment of an LEDapparatus;

FIG. 4B is a top view of the LED apparatus shown in FIG. 4A;

FIG. 5A is a cross-sectional view of a further embodiment of an LEDapparatus;

FIG. 5B is a top view of the LED apparatus shown in FIG. 5A;

FIG. 6A is a cross-sectional view of a further embodiment of an LEDapparatus;

FIG. 6B is a top view of the LED apparatus shown in FIG. 6A; and

FIGS. 7-9 are cross-sectional side views of various embodiments of anLED apparatus.

DETAILED DESCRIPTION

In some aspects, solid state lighting apparatuses, LED devices and/orsystems, and methods for producing the same, described herein cancomprise various solid state light emitter electrical configurations,color combinations, and/or circuitry components for providing solidstate lighting apparatuses having improved efficiency, improved emissionprofiles, enhanced output and/or optimized color production. Apparatusesand methods such as those disclosed herein advantageously cost less, aremore efficient, vivid, uniform, and/or brighter than some othersolutions.

Unless otherwise defined, terms used herein should be construed to havethe same meaning as commonly understood by one of ordinary skill in theart to which this subject matter belongs. It will be further understoodthat terms used herein should be interpreted as having a meaning that isconsistent with the respective meaning in the context of thisspecification and the relevant art, and should not be interpreted in anidealized or overly formal sense unless expressly so defined herein.

Aspects of the subject matter are described herein with reference tosectional, perspective, elevation, and/or plan view illustrations thatare schematic illustrations of idealized aspects of the subject matter.Variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected, such that aspects of the subject matter should not beconstrued as limited to particular shapes illustrated herein. Thissubject matter can be embodied in different forms and should not beconstrued as limited to the specific aspects or embodiments set forthherein. In the drawings, the size and relative sizes of layers andregions can be exaggerated for clarity.

Unless the absence of one or more elements is specifically recited, theterms “comprising”, “including”, and “having” as used herein should beinterpreted as open-ended terms that do not preclude the presence of oneor more elements. Like numbers refer to like elements throughout thisdescription.

It will be understood that when an element such as a layer, region, orsubstrate is referred to as being “on” another element, it can bedirectly on the other element or intervening elements can be present.Moreover, relative terms such as “on”, “above”, “upper”, “top”, “lower”,or “bottom” are used herein to describe one structure's or portion'srelationship to another structure or portion as illustrated in thefigures. It will be understood that relative terms such as “on”,“above”, “upper”, “top”, “lower” or “bottom” are intended to encompassdifferent orientations of the apparatus in addition to the orientationdepicted in the figures. For example, if the apparatus in the figures isturned over, structure or portion described as “above” other structuresor portions would now be oriented “below” the other structures orportions.

The terms “electrically activated emitter(s)” and “emitter(s)” as usedherein are synonymous terms and refer to any device capable of producingvisible or near visible (e.g., from infrared to ultraviolet) wavelengthradiation, including for example but not limited to, xenon lamps,mercury lamps, sodium lamps, incandescent lamps, and solid stateemitters, including LEDs or LED chips, organic light emitting diodes(OLEDs), and lasers.

The terms “solid state light emitter(s)”, “solid state emitter(s)”, and“light emitter(s)” are synonymous terms and refer to an LED chip, alaser diode, an organic LED chip, and/or any other semiconductor devicepreferably arranged as a semiconductor chip that comprises one or moresemiconductor layers, which can comprise silicon, silicon carbide,gallium nitride and/or other semiconductor materials, a substrate whichcan comprise sapphire, silicon, silicon carbide and/or othermicroelectronic substrates, and one or more contact layers which cancomprise metal and/or other conductive materials.

The terms “groups”, “segments”, “strings”, and “sets” as used herein aresynonymous terms. As used herein, these terms generally describe howmultiple LEDs are electrically connected, such as in series, inparallel, in mixed series/parallel, in common anode, or in common anodeconfigurations among mutually exclusive groups/segments/sets. Thesegments of LEDs can be configured in a number of different ways and mayhave circuits of varying functionality associated therewith (e.g. drivercircuits, rectifying circuits, current limiting circuits, shunts, bypasscircuits, etc.), as discussed, for example, in commonly assigned andco-pending U.S. patent application Ser. No. 12/566,195, filed on Sep.24, 2009, U.S. patent application Ser. No. 13/769,273, filed on Feb. 15,2013, U.S. patent application Ser. No. 13/769,277 filed on Feb. 15,2013, U.S. patent application Ser. No. 13/235,103, filed on Sep. 16,2011, U.S. patent application Ser. No. 13/235,127, filed on Sep. 16,2011, and U.S. Pat. No. 8,729,589, which issued on May 20, 2014, thedisclosure of each of which is hereby incorporated by reference hereinin the entirety.

The term “targeted” refers to configurations of LED chip segments thatare configured to provide a pre-defined lighting characteristic that isa specified parameter for the lighting apparatus. For example, thetargeted spectral power distribution can describe the characteristic ofthe light that is generated at a particular power, current, or voltagelevel.

Apparatuses, systems, and methods as disclosed herein can utilize redchips, green chips, and blue chips. In some aspects, chips for use inblue-shifted yellow light (BSY) devices can target different bins as setforth in Table 1 of commonly owned, assigned, and co-pending U.S. patentapplication Ser. No. 12/257,804, published as U.S. Pat. Pub. No.2009/0160363, the disclosure of which is incorporated by referenceherein in the entirety. Apparatuses, systems, and methods herein canutilize, for example, ultraviolet (UV) chips, cyan chips, blue chips,green chips, red chips, amber chips, and/or infrared chips.

The term “substrate” as used herein in connection with lightingapparatuses refers to a mounting member or element on which, in which,or over which, multiple solid state light emitters (e.g., LEDs) can bearranged, supported, and/or mounted. A substrate can be, e.g., acomponent substrate, a chip substrate (e.g., an LED substrate), or asub-panel substrate. Exemplary substrates useful with lightingapparatuses as described herein can for example comprise printed circuitboards (PCBs) and/or related components (e.g., including but not limitedto metal core printed circuit boards (MCPCBs), flexible circuit boards,dielectric laminates, ceramic based substrates, and the like), ceramicor metal boards having FR4 and/or electrical traces arranged on one ormultiple surfaces thereof, high reflectivity ceramics (e.g., alumina)support panels, and/or mounting elements of various materials andconformations arranged to receive, support, and/or conduct electricalpower to solid state emitters. Electrical traces described hereinprovide electrical power to the emitters for electrically activating andilluminating the emitters. Electrical traces may be visible and/orcovered via a reflective covering, such as a solder mask material, Ag,or other suitable reflector.

In some embodiments, one substrate can be used to support multiplegroups of solid state light emitters in addition to at least some othercircuits and/or circuit elements, such as a power or current drivingcomponents and/or current switching components. In other aspects, two ormore substrates (e.g., at least a primary substrate and one or moresecondary substrate or substrates) can be used to support multiplegroups of solid state light emitters in addition to at least some othercircuits and/or circuit elements, such as a power or current drivingcomponents and/or temperature compensation components. The first andsecond (e.g., primary and secondary) substrates can be disposed aboveand/or below each other and along different planes, adjacent (e.g.,side-by-side) to each other, have one or more co-planar surfacesdisposed adjacent each other, arranged vertically, arrangedhorizontally, and/or arranged in any other orientation with respect toeach other.

LEDs useable with lighting apparatuses as disclosed herein can comprisehorizontal structures (with both electrical contacts on a same side ofthe LED chip) and/or vertical structures (with electrical contacts onopposite sides of the LED chip). A horizontally structured chip (with orwithout the growth substrate), for example, can be flip chip bonded(e.g., using solder) to a carrier substrate or printed circuit board(PCB), or wire bonded. A vertically structured chip (without or withoutthe growth substrate) can have a first terminal solder bonded to acarrier substrate, mounting pad, or printed circuit board (PCB), andhave a second terminal wire bonded to the carrier substrate, electricalelement, or PCB.

Electrically activated light emitters, such as solid state emitters, canbe used individually or in groups to emit light to stimulate emissionsof one or more lumiphoric materials (e.g., phosphors, scintillators,lumiphoric inks, quantum dots), and generate light at one or more peakwavelengths, or of at least one desired perceived color (includingcombinations of colors that can be perceived as white). Inclusion oflumiphoric (also called ‘luminescent’) materials in lighting apparatusesas described herein can be accomplished by an application of a directcoating of the material on lumiphor support elements or lumiphor supportsurfaces (e.g., by powder coating, inkjet printing, or the like), addingsuch materials to lenses, and/or by embedding or dispersing suchmaterials within lumiphor support elements or surfaces. Methods forfabricating LEDs having a planarized coating of phosphor integratedtherewith are discussed by way of example in U.S. Patent ApplicationPublication No. 2008/0179611, filed on Sep. 7, 2007, to Chitnis et al.,the disclosure of which is hereby incorporated by reference herein inthe entirety.

Other materials, such as light scattering elements (e.g., particles)and/or index matching materials can be associated with a lumiphoricmaterial-containing element or surface. Apparatuses and methods asdisclosed herein can comprise LEDs of different colors, one or more ofwhich can be white emitting (e.g., including at least one LED with oneor more lumiphoric materials).

In some aspects, one or more short wavelength solid state emitters(e.g., blue and/or cyan LEDs) can be used to stimulate emissions from amixture of lumiphoric materials, or discrete layers of lumiphoricmaterial, including red, yellow, and green lumiphoric materials. LEDs ofdifferent wavelengths can be present in the same group of solid stateemitters, or can be provided in different groups of solid stateemitters. A wide variety of wavelength conversion materials (e.g.,luminescent materials, also known as lumiphors or lumiphoric media,e.g., as disclosed in U.S. Pat. No. 6,600,175, issued on Jul. 29, 2003,and U.S. Patent Application Publication No. 2009/0184616, filed on Oct.9, 2008, each disclosure of which is hereby incorporated by referenceherein in the entirety), are well-known and available to persons ofskill in the art.

In some aspects, lighting apparatuses and systems as described hereincomprise multiple sets of solid state light emitters targeting differentcolors (e.g., one set targeting a first color and at least a second settargeting a second color that is different than the first color). Insome aspects, each set of the multiple sets comprises at least two solidstate light emitters of a same color (e.g., the peak wavelengthscoincide). In some aspects, each set of the multiple sets of solid stateemitters is adapted to emit one or more different color(s) of light. Insome aspects, each set of the multiple sets of solid state emitters isadapted to emit one or more color(s) of light that differ relative toone another (e.g., with each set of solid state emitters emitting atleast one peak wavelength that is not emitted by another set of solidstate emitters). Aspects of targeting and selectively activating sets ofsolid state emitters according to the present subject matter may beprovided using the circuitry and/or techniques described in commonlyassigned and co-pending U.S. patent application Ser. No. 14/221,839, thedisclosure of which was previously incorporated hereinabove byreference.

The term “color” in reference to a solid state emitter refers to thecolor and/or wavelength of light that is emitted by the chip uponpassage of electrical current therethrough.

Some embodiments of the present subject matter may use solid stateemitters, emitter packages, fixtures, luminescent materials/elements,power supply elements, control elements, and/or methods such asdescribed in U.S. Pat. Nos. 7,564,180; 7,456,499; 7,213,940; 7,095,056;6,958,497; 6,853,010; 6,791,119; 6,600,175, 6,201,262; 6,187,606;6,120,600; 5,912,477; 5,739,554; 5,631,190; 5,604,135; 5,523,589;5,416,342; 5,393,993; 5,359,345; 5,338,944; 5,210,051; 5,027,168;5,027,168; 4,966,862, and/or 4,918,497, and U.S. Patent ApplicationPublication Nos. 2009/0184616; 2009/0080185; 2009/0050908; 2009/0050907;2008/0308825; 2008/0198112; 2008/0179611, 2008/0173884, 2008/0121921;2008/0012036; 2007/0253209; 2007/0223219; 2007/0170447; 2007/0158668;2007/0139923, and/or 2006/0221272; U.S. patent application Ser. No.11/556,440, filed on Dec. 4, 2006; with the disclosures of the foregoingpatents, published patent applications, and patent application serialnumbers being hereby incorporated by reference as if set forth fullyherein.

The terms “lighting apparatus” and “module” as used herein aresynonymous, and are not limited, except that it is capable of emittinglight. That is, a lighting apparatus can be a device or apparatus thatilluminates an area or volume, e.g., a structure, a swimming pool orspa, a room, a warehouse, an indicator, a road, a parking lot, avehicle, signage (e.g., road signs, a billboard), a ship, a toy, amirror, a vessel, an electronic device, a boat, an aircraft, a stadium,a computer, a remote audio device, a remote video device, a cell phone,a tree, a window, an LCD display, a cave, a tunnel, a yard, a lamppost,or a device or array of devices that illuminate an enclosure, or adevice that is used for edge or back-lighting (e.g., backlight poster,signage, LCD displays), light bulbs, bulb replacements (e.g., forreplacing AC incandescent lights, low voltage lights, fluorescentlights, etc.), outdoor lighting, security lighting, exterior residentiallighting (wall mounts, post/column mounts), ceiling fixtures/wallsconces, under cabinet lighting, lamps (floor and/or table and/or desk),landscape lighting, track lighting, task lighting, specialty lighting,rope lights, ceiling fan lighting, archival/art display lighting, highvibration/impact lighting-work lights, etc., mirrors/vanity lighting,spotlighting, high-bay lighting, low-bay lighting, or any other lightemitting device.

Phosphor and phosphor compounds as disclosed herein can in some aspectscomprise one or more of a wide variety of wavelength conversionmaterials or color conversion components including luminescentmaterials. Examples of luminescent materials (lumiphors) includephosphors, Cerium-doped Yttrium Aluminum Garnet (YAG) (e.g. LuAG:Ce),Nitrides, Oxy-Nitrides, scintillators, day glow tapes, nanophosphors,quantum dots (e.g., such as provided by NNCrystal US Corp.,Fayetteville, Ark.), and inks that glow in the visible spectrum uponillumination with (e.g., ultraviolet) light. Inclusion of lumiphors inwavelength conversion components or related components as disclosedherein, in conjunction with solid state light emitters and LEDs, can beaccomplished by providing layers (e.g., coatings) of such materials oversolid state emitters and/or by dispersing luminescent materials to aclear encapsulant (e.g., epoxy-based or silicone-based curable resin orother polymeric matrix) arranged to cover or partially cover one or moresolid state light emitters. One or more luminescent materials useable indevices as described herein may be down-converting or up-converting, orcan include a combination of both types.

Wavelength conversion materials can provide benefits including, forexample, improved long term reliability (e.g., improved properties ataround 1000 hours or more and 85° C., 105° C., and/or 125° C.),decreased bubbling around solid state light emitters, a larger viewingangle, lower dCCT color spread, cooler phosphor temperatures, brighterlight emission, improved sulfur resistance, and/or a smaller color pointspread, including all or any combination of such features.

The presently disclosed subject matter is directed to embodiments of LEDstructures having a light source that comprises LEDs. The LED packagescan be arranged in different ways and are relatively small, while at thesame time are efficient, reliable and cost effective. The embodimentsaccording to the disclosure herein can have different shapedencapsulants, and can emit light with improved or similar efficiencycompared to similar LED packages with fully hemispheric encapsulants. Insome embodiments where a plurality of LEDs are mounted on a substrate,the spacing between each LED chip can be controlled to optimize theintensity of light output from the LED package. The LED packagesaccording to the disclosure herein can also be smaller and lessexpensive to manufacture.

The disclosure herein is described with reference to exampleembodiments, but it is understood that the disclosure herein can beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein. In particular, the disclosureherein is described below in regards to certain LED apparatuses havingLEDs in different configurations, but it is understood that thedisclosure herein can be used for many other LED packages with other LEDconfigurations. LED packages using the disclosure herein can also havemany different shapes beyond those described below, such as rectangular,and the solder pads and attach pads can be arranged in many differentways. In other embodiments, the emission intensity of the differenttypes of LEDs can be controlled to vary the overall LED packageemission.

The embodiments described herein are with reference to an LED or LEDs,but in accordance with the disclosure herein and in some aspects LEDs asused herein can include LED chips or any other suitable structure orstructures. For example, LEDs as used herein can be individual junctionsof a monolithic LED. For example, instead of being completely separateLED chips, the LEDs can each be a LED region all on a common substratethat can have different types of monolithic junctions. A mesa betweenthe LEDs and on the common substrate can extend to certain layers or canextend all the way to or from the common substrate. Therefore, amonolithic LED can comprise more than one LED junctions on a commonsubstrate, and the gaps between the LEDs can be formed by the mesas thatcan at least partially separate the LEDs.

The components described herein can have different shapes and sizesbeyond those shown, and one or different numbers of LEDs can beincluded. It is also understood that the embodiments described belowutilize co-planar light sources, but it is understood that non co-planarlight sources can also be used. It is also understood that an LED lightsource may be comprised of multiple LEDs that may have differentemission wavelengths. As mentioned above, in some embodiments at leastsome of the LEDs can comprise blue emitting LEDs covered with a yellowphosphor along with red emitting LEDs, resulting in a white lightemission from the LED package. In multiple LED packages, the LEDs can beserially interconnected or can be interconnected in different serial andparallel combinations.

Coatings, encapsulants, encapsulant layers, and the like are disclosedherein and can comprise any material that provides mechanical, chemical,and/or environmental protection to a substrate, reflective layer, orother LED component. A coating, encapsulant and/or encapsulant layer canbe configured in some embodiments as a layer that covers a substantiallyhorizontal or vertical surface, and in some aspects can comprise a layerdisposed on top of another layer, surface or structure whether or not itfully surrounds all sides of the other layer, surface or structure. Insome embodiments a coating, encapsulant and/or encapsulant layer cancomprise or consist of a dielectric as disclosed herein. It is alsounderstood that when an feature or element such as a layer, region,encapsulant or submount may be referred to as being “on” anotherelement, it can be directly on the other element or intervening elementsmay also be present. Furthermore, relative terms such as “inner”,“outer”, “upper”, “above”, “lower”, “beneath”, and “below”, and similarterms, may be used herein to describe a relationship of one layer oranother region. It is understood that these terms are intended toencompass different orientations of the device in addition to theorientation depicted in the figures.

Embodiments of the present disclosure are described herein withreference to cross-sectional view illustrations that are schematicillustrations of embodiments of the disclosure. As such, the actualthickness of the layers can be different, and variations from the shapesof the illustrations as a result, for example, of manufacturingtechniques and/or tolerances are expected. Embodiments of the disclosureshould not be construed as limited to the particular shapes of theregions illustrated herein but are to include deviations in shapes thatresult, for example, from manufacturing. A region illustrated ordescribed as square or rectangular will typically have rounded or curvedfeatures due to normal manufacturing tolerances. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the precise shape of a region of a device andare not intended to limit the scope of the disclosure herein.

Coating materials disclosed herein can in some aspects comprise a numberof encapsulating layers, coatings and/or dielectric materials andcompounds, including for example silicon oxide, silicon nitride,aluminum oxide, titanium dioxide, non-metallic oxides, non-metallicnitrides, tantalum oxide, aluminum, nickel, titanium, tungsten,platinum, combinations thereof or alloys thereof, etc. In some aspectssuch encapsulants, coatings and/or dielectrics can comprise one or morematerials arranged to provide desired electrical isolation and highthermal conductivity. For example, a dielectric can provide a desiredelectrical isolation between electrical traces and/or sets of solidstate emitters. In some aspects, such substrates can comprise ceramicsuch as alumina (Al2O3), aluminum nitride (AlN), silicon carbide (SiC),silicon, or a plastic or polymeric material such as polyimide,polyester, metal, etc.

Disclosed herein are LED apparatuses or devices that are particularlyuseful for providing bright light from LEDs mounted on a substrate. Byproviding a first light-transmissive material or layer encapsulating theLED and a subsequent application of a reflective material or layer, thedirection and sharpness of emitted light can be more easily controlled.In one aspect, an LED apparatus can comprise an encapsulation materialover a substrate and one or more LED, which are covered in an opticallayer. A reflective material can be disposed over the encapsulationmaterial so that the reflective material defines and provides or definesan opening or window such that the reflective material defines theopening where the encapsulation material is not covered by thereflective material which allows light to pass through the opening fromthe one or more LED. This allows light to escape or pass from the LEDapparatus in a predetermined, controlled and directed manner. Theencapsulation material and the reflective material can be disposed suchthat the materials extend to the edge of the substrate. In some aspects,a surface formed by the substrate, the encapsulation material, and thereflective material can be a continuous surface, such as for example, aplanar surface. An LED apparatus as disclosed herein can furthercomprise a plurality of LEDs configured to emit light that is a samecolor or are different colors.

In another aspect, an LED apparatus can comprise an encapsulationmaterial as disclosed hereinabove, but in this case the reflectivematerial can be disposed on one or more lateral surface of theencapsulation material at an angle to the surface of the substrate. Thiscreates a reflective “wall” for directing the light obliquely from theapparatus.

In a further aspect, a method of producing a panel of such LEDs isdescribed. The method includes applying an encapsulation material orlayer over a substrate and one or more LED and then applying an opaquereflective material or layer over the encapsulation material. The methodcan optionally include removing a portion of the opaque reflectivematerial or layer to expose a further portion of the clear encapsulationmaterial. The layers can be removed by any suitable technique, such asfor example by grinding, sanding, buffing, or lapping. The resultingsurface can then further be optionally treated to achieve a desiredfinish, in a range from matte to high gloss.

According to existing art, an LED apparatus generally designated 100 canbe provided with a substrate 10, one or more LED 20, and the device canbe encapsulated with a clear or light-transmissive encapsulationmaterial 30, as shown in FIG. 1. The encapsulation material can be, forexample, compounds such as described above.

Encapsulation material 30 can be applied in any suitable manner and in avariety of ways, such as for example, by molding, dispensing, spraying,or any other suitable method. In this manner LED 20 is protected fromcorrosion and light L is dispersed in a wide viewing angle abovesubstrate 10. However, there may be applications where it is desired tohave a prescribed viewing angle rather than a fully open viewing angle.The devices and methods disclosed herein provide a solution to thisneed.

In one embodiment of an LED depicted for example in FIG. 2, an LEDapparatus generally designated 200 has a substrate 10, one or more LED20 disposed over substrate 10, and an encapsulation material 30 disposedover at least a portion of substrate 10 and LED 20. Encapsulationmaterial 30 can be a light-transmissive layer. LED apparatus 200 furthercomprises a reflective material or layer 40 that can be disposed againstand can cover a portion of encapsulation material 30, while providing anopening, window, or area generally designated 50. Light can be emittedfrom LED 20, through encapsulation material 30 and pass for exampleupwardly in multiple different directions as represented for example bythe arrows in FIG. 2. The light will be reflected by reflective materialor layer 40, which creates or defines the window or aperture wherereflective material or layer 40 does not cover encapsulation materialsor layer 30. Reflective material or layer 40 therefore allows passage oflight through area 50, concentrating the light output through a definedviewing angle and effectively creating an integrated component-leveloptic. Reflective material or layer 40 can be a light-colored layer suchas titania and/or other reflective material(s), or reflective materialor layer 40 can also be a black material or layer which acts as areflective surface when disposed on light-transmissive encapsulationmaterial 30. In this example embodiment LED apparatus 200 has continuousplanar surfaces at the boundaries of substrate 10.

FIGS. 3A and 3B depict examples of possible geometries for areas on LEDapparatuses 200A and 200B, respectively. For example, FIG. 3A shows LEDapparatus 200A with area generally designated 50A having a roundconfiguration or window through which encapsulation material 30A isvisible. In another example shown in FIG. 3B, LED apparatus 200B hasarea generally designated 50B having a rectangular configuration orwindow through which encapsulation material 30B is visible. It is to beunderstood that these examples are non-limiting and that any suitableconfiguration or variety of configurations can be used. For example, theencapsulation material or layer can be dome, spherical, bullet,pyramidal, or otherwise shaped, and the reflective material or layer canbe suitably shaped as desired against the encapsulation material orlayer.

Referring to FIGS. 4A-4B and in other embodiments, the thickness ofreflective material or layer 40 can be adjusted to affect the amount oflight emitted from LED apparatus 200. For example, reflective materialor layer 40 can be disposed on encapsulation material 30C. Reflectivematerial or layer 40 can initially have a surface S₀ above substrate 10as depicted in FIGS. 4A-4B, FIG. 4B being a top view of FIG. 4A. Theresulting window can be an opening or area generally designated 50C.Opening 50C can in some embodiments be smaller than a width of LED 20,creating a prescribed viewing angle. Surface S₀ of reflective materialor layer 40 can be then polished or removed in any suitable fashion inorder to fine-tune the viewing angle of LED 20. FIGS. 5A-5B show anembodiment of LED apparatus 200 from side and top views, respectively,after surface S₀ has been removed. In FIGS. 5A-5B, surface S₁ is at areduced height from surface S₀. This decreases the overall height of LEDapparatus 200 and creates a larger window in reflective material orlayer 40, resulting in a larger opening or area generally designated 50Dfor light to escape or pass. In this embodiment, opening 50D can besubstantially the same width as a width of LED 20.

Similarly, FIGS. 6A-6B show an embodiment of LED apparatus 200 from sideand top views, respectively. In this embodiment surface S₀ has beenremoved to a greater extent, resulting in surface S₂. The resultingopening or area generally designated 50E can be larger than a width ofLED 20.

In another example embodiment shown in FIG. 7, an LED apparatusgenerally designated 300 has a substrate 10, one or more LED 20 disposedover substrate 10, and a light-transmissive encapsulation material 32disposed over at least a portion of substrate 10 and LED 20.Encapsulation material 32 can have a dome shape with vertical walls, andreflective material or layer 42 can be disposed on encapsulationmaterial 32 except for the apex of the dome, forming a small openingwhere encapsulation material 32 is not covered by reflective material42. In this way light from LED 20 can be emitted in a narrow viewingangle. As with previous embodiments, the top surface of LED apparatus300 comprising the opening can be polished or removed in any suitablefashion in order to modify the viewing angle for light from LED 20.

In an alternate embodiment, an LED apparatus can have a substrate, oneor more LED, an encapsulant, and a reflective material disposed on oneor more lateral surface of the encapsulation material and also incontact with a surface of the substrate. Examples of this embodiment aredepicted in FIGS. 8 and 9. For example, in FIG. 8 an LED apparatusgenerally designated 400 has a substrate 10, one or more LED 20 disposedover substrate 10, and a light-transmissive encapsulation material 34,which forms a generally dome shape with at least one planar portionperpendicular or at an angle to the upper surface of substrate 10.Reflective material or layer 44 is disposed on a planar portion or sideof encapsulation material 34. In this way light can be reflected in adirection away from the planar portion or portions.

FIG. 9 depicts a similar embodiment of LED apparatus generallydesignated 500. LED apparatus 500 has a substrate 10, one or more LED 20disposed over substrate 10, a light-transmissive encapsulation material36, and a reflective material or layer 46. Encapsulation material 36 inthis case has a substantially flat outer surface at an angle fromsubstrate 10, and a planar portion perpendicular or at an angle tosubstrate 10. Encapsulation material 46 is disposed perpendicular tosubstrate 10 on the planar portion of encapsulation material 36. It isto be understood that these examples are non-limiting and that anysuitable configuration or variety of configurations can be used. Forexample, the surface of the encapsulation material can be disposed at anacute angle to the surface of the substrate, and the reflective materialcan be disposed on more than one lateral side of the encapsulationmaterial. The lateral sides of the encapsulation material can further becurved rather than planar.

While the subject matter has been has been described herein in referenceto specific aspects, features, and illustrative embodiments, it will beappreciated that the utility of the subject matter is not thus limited,but rather extends to and encompasses numerous other variations,modifications and alternative embodiments, as will suggest themselves tothose of ordinary skill in the field of the present subject matter,based on the disclosure herein.

Aspects disclosed herein can, for example and without limitation,provide one or more of the following beneficial technical effects:reduced cost of providing solid state lighting apparatuses; improved ormore robust optical control; reduced size, volume, or footprint of solidstate lighting apparatuses; improved efficiency; improved colorrendering; improved thermal management; simplified circuitry; improvedcontrast, improved viewing angle; improved color mixing; improvedreliability; and/or simplified DC or AC operability.

Various combinations and sub-combinations of the structures and featuresdescribed herein are contemplated and will be apparent to a skilledperson having knowledge of this disclosure. Any of the various featuresand elements as disclosed herein can be combined with one or more otherdisclosed features and elements unless indicated to the contrary herein.Correspondingly, the subject matter as hereinafter claimed is intendedto be broadly construed and interpreted, as including all suchvariations, modifications and alternative embodiments, within its scopeand including equivalents of the claims.

1. A light emitting diode (LED) apparatus, comprising: a substrate; oneor more light emitting diode (LED) disposed over the substrate; alight-transmissive encapsulation material disposed over the one or moreLED; and a reflective material disposed on a portion of theencapsulation material such that the reflective material defines anopening where the encapsulation material is not covered by thereflective material to allow light to pass through the opening from theone or more LED, wherein the opening comprises an area smaller than anarea of the encapsulation material adjacent to the substrate.
 2. The LEDapparatus of claim 1, wherein the encapsulation material is molded. 3.The LED apparatus of claim 1, wherein the molded encapsulation materialis formed in a conical, dome, hemispherical, bullet, or pyramidal shape.4. The LED apparatus of claim 1, wherein the encapsulation material andthe reflective material extend to the edges of the substrate and form acontinuous surface with the substrate.
 5. The LED apparatus of claim 1,wherein the opening area is greater than a surface area of the one ormore LED.
 6. The LED apparatus of claim 1, wherein the opening area issubstantially a same size as a surface area of the one or more LED. 7.The LED apparatus of claim 1, wherein the opening area is smaller than asurface area of the one or more LED.
 8. The LED apparatus of claim 1,wherein the reflective material comprises titania and/or otherreflective material.
 9. The LED apparatus of claim 1, wherein a portionof the reflective material is removed from a region of the encapsulationmaterial to result in an increased size of the opening.
 10. The LEDapparatus of claim 1, comprising a plurality of LEDs, wherein theplurality of LEDs are configured to emit light that is a same color ordifferent colors.
 11. A light emitting diode (LED) apparatus,comprising: a substrate; one or more light emitting diode (LED) disposedover the substrate; a light-transmissive encapsulation material disposedover the one or more LED; and a reflective material disposed against oneor more lateral surface of the encapsulation material and in contactwith the substrate in a form of a substantially planar wall.
 12. The LEDapparatus of claim 11, wherein the encapsulation material is molded. 13.The LED apparatus of claim 11, wherein the encapsulation material isformed in a dome or pyramidal shape disposed asymmetrically over thesubstrate.
 14. The LED apparatus of claim 11, wherein the encapsulationmaterial and the reflective material extend to the edges of thesubstrate and form a continuous surface with the substrate.
 15. The LEDapparatus of claim 11, wherein the planar wall of the reflectivematerial is substantially perpendicular to the substrate.
 16. The LEDapparatus of claim 11, comprising a plurality of LEDs, wherein theplurality of LEDs are configured to emit light that is a same color ordifferent colors.
 17. A method of producing a light emitting diode (LED)apparatus, the method comprising: providing a substrate with at leastone LED disposed over the substrate; applying an encapsulation materialover the at least one LED; and applying a reflective material on aportion of the encapsulation material such that the reflective materialdefines an opening where the encapsulation material is not covered bythe reflective material to allow light to pass through the opening fromthe one or more LED.
 18. The method of claim 17, further comprisingremoving the reflective material in a region above the at least one LEDto expose a further portion of the encapsulation material.
 19. Themethod of claim 18, further comprising lapping or buffing the exposedencapsulation material to result in a surface finish from matte to highgloss.
 20. A method of controlling light output from a light emittingdiode (LED) apparatus, comprising: providing an LED apparatus,comprising: a substrate; one or more LED disposed over the substrate;and a encapsulation material disposed over the one or more LED; andcontrolling light output from the one or more LED by applying a layer oflight-transmissive reflective material on a portion of the encapsulationmaterial such that the reflective material creates an opening where theencapsulation material is not covered by the reflective material toallow light to pass through the opening from the one or more LED. 21.The method of claim 20, further comprising removing a portion of thereflective material from the encapsulation material to increase a sizeof the opening.